使用APPLY UPDATE some_table SET some_row = another_row, some_row2 = another_row/2 FROM some_table st CROSS APPLY (SELECT TOP 1 another_row FROM another_table at WHERE at.shared_id=st.shared_id) WHERE ... Run Code Online (Sandbox Code Playgroud) 在更新语句中使用交叉应用归档...
UPDATEdbo.T1SET(col1, col2, col3)=(SELECTcol1, col2, col3FROMdbo.T2WHERET2.keycol=T1.keycol)WHEREEXISTS(SELECT*FROMdbo.T2WHERET2.keycol=T1.keycolANDT2.col4='ABC'); PS:虽然本书作者说要使用标准SQL来进行UPDATE或DELETE,但是实际使用中笔者认为若是对生产环境中的表操作时还是使用T-SQL的...
如果有两个 WHEN MATCHED 子句,一个必须指定 UPDATE 操作,另一个必须指定 DELETE 操作。 如果在 <merge_matched> 子句中指定了 UPDATE,并且根据 <merge_search_condition> <table_source> 中有多行与 target_table 中的一行匹配, SQL Server 便会返回错误。 MERGE 语句无法多次更新同一行,也无法更新和删除同...
This takes you to the article String Functions (Transact-SQL). What you will learn This tutorial shows you how to create a database, create a table in the database, insert data into the table, update the data, read the data, delete the data, and then delete the table. You will ...
T-SQL is proprietary, while SQL is an open format. Joins in T-SQL Joins in T-SQL are clauses used to combine rows from two or more tables, based on a related column between them. Joins specify how SQL should use data from one table to select the rows in another table. Several oper...
FeatureFileTableMemory-optimized tables cannot be created as file tables. Remove the argumentAS FileTablefrom theCREATE TABLEstatement OperationUpdate of primary key columnsPrimary key columns in memory-optimized tables and table types cannot be updated. If the primary key needs to be updated, delete...
SQL USE[TestData]; GOCREATEUSER[Mary]FORLOGIN [computer_name\Mary]; GO Now, Mary has access to both SQL Server and theTestDatadatabase. Create views and stored procedures As an administrator, you can execute the SELECT from theProductstable and thevw_Namesview, and execute thepr_Namesproce...
DML锁分类表表1Oracle的TM锁类型锁 模 式锁描述解释SQL操 作0none1NULL空Select2SS(Row-S)行级共享锁, 其他对象只 能查询这些 数据行Selectforu pdate 、Lockfor up date、Lo 10、ckrowshare3SX(Row-X)行级排它锁,Insert 、Update、Delete、在提交前不允许做DML操作Lockrowshare4S(Share)共享锁Create ...
EXECUTE 'CREATE TABLE link_emp (idemp1 integer, idemp2 integer)'; Run anonymous block BEGIN ... END; DO $$DECLARE BEGIN ... END$$; For more information, see Basic Statements in the PostgreSQL documentation. Document Conventions Databases and schemas for T-SQL T...
Another T-SQL enhancement in Yukon allows you to return output from Data Manipulation Language (DML) statements other than SELECT (INSERT, UPDATE, DELETE). A new OUTPUT clause allows you to request that the old/new images of the columns be returned by referring to the INSERTED and DELETED t...